{"id":2667,"date":"2013-05-17T16:58:04","date_gmt":"2013-05-17T07:58:04","guid":{"rendered":"http:\/\/yasu2.prosou.nu\/blog\/index.php\/2013\/05\/17\/freebsd_device_driver_dma\/"},"modified":"2013-05-17T16:58:04","modified_gmt":"2013-05-17T07:58:04","slug":"freebsd_device_driver_dma","status":"publish","type":"post","link":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/2013\/05\/17\/2667\/","title":{"rendered":"FreeBSD device driver \u3067 DMA"},"content":{"rendered":"<p>FreeBSD \u3067\u30c7\u30d0\u30a4\u30b9\u30c9\u30e9\u30a4\u30d0\u66f8\u3044\u3066 DMA \u3092\u52d5\u304b\u3059\u305f\u3081\u306e\u3044\u308d\u3044\u308d\u3002\u3068\u308a\u3042\u3048\u305a\u53c2\u8003\u306b\u306a\u308a\u305d\u3046\u306a\u306e\u306f\u3001<\/p>\n<ul>\n<li><a href=\"http:\/\/www.freebsd.org\/doc\/en_US.ISO8859-1\/books\/arch-handbook\/isa-driver-busmem.html\">FreeBSD Architecture Handbook: Bus Memory Mapping<\/a>\n<li><a href=\"http:\/\/www.jp.freebsd.org\/cgi\/mroff.cgi?sect=9&#038;subdir=man&#038;lc=1&#038;cmd=&#038;dir=jpman-6.4.2\/man&#038;man=bus_dma\">bus_dma (9)\n<li><a href=\"http:\/\/people.freebsd.org\/~jhb\/papers\/drivers\/slides.pdf\">Writing and Adapting Device Drivers for FreeBSD<\/a>\n<li><a href=\"http:\/\/www.bsdcan.org\/2006\/papers\/freebsd.device.driver.slides.pdf\">How to write a device driver in FreeBSD (PDF)<\/a>\n<\/ul>\n<p>\u3053\u306e\u3042\u305f\u308a\u3002\u5b9f\u4f8b\u306f \/usr\/src\/sys\/dev \u306e\u4e0b\u3042\u305f\u308a\u3092\u307f\u308c\u3070\u3044\u304f\u3089\u3067\u3082\u3042\u308b\u3051\u308c\u3069\u3001\u3068\u308a\u3042\u3048\u305a\u53c2\u8003\u306b\u3057\u305f\u306e\u306f \/usr\/src\/sys\/dev\/hifn\/hifn7751.c \u3068\u304b\u3002<br \/>\nbus_alloc_resources() \u3068\u304b\u3067 BAR \u306e\u5024\u3092\u8aad\u307f\u51fa\u3057\u305f\u308a\u3001DMAC \u3092\u5236\u5fa1\u3059\u308b\u305f\u3081\u306e\u30ec\u30b8\u30b9\u30bf\u3092 mmap() \u3067\u304d\u308b\u3088\u3046\u306b\u3059\u308b\u3042\u305f\u308a\u306f\u4eca\u56de\u306f\u3068\u308a\u3042\u3048\u305a\u7701\u7565\u3057\u3066\u3001DMA \u306e\u30a2\u30af\u30bb\u30b9\u5148\u306b\u306a\u308b\u30e1\u30a4\u30f3\u30e1\u30e2\u30ea\u4e0a\u306e\u9818\u57df\u3092\u78ba\u4fdd\u3059\u308b\u305f\u3081\u306e\u624b\u9806\u3092\u307e\u3068\u3081\u3066\u304a\u304f\u3053\u3068\u306b\u3057\u307e\u3059\u3002<\/p>\n<ol>\n<li>bus_dma_tag_create() <br \/>\n\u30c7\u30d0\u30a4\u30b9\u306eDMAC\u306b\u95a2\u3059\u308b\u3044\u308d\u3044\u308d\u3092\u8a2d\u5b9a\u3059\u308b\u3002\u305f\u3068\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u3053\u3068\u3002\u3053\u308c\u3092 DMA tag \u3068\u3044\u3046\u3002<\/p>\n<ul>\n<li>\u4f55\u30d0\u30a4\u30c8\u5358\u4f4d\u3067DMA\u3067\u304d\u308b\u304b(1\u30d0\u30a4\u30c8\u5358\u4f4d\u304b\u30014\u30d0\u30a4\u30c8\u5358\u4f4d\u304b\u3001\u306a\u3069)\n<li>DMA\u53ef\u80fd\u306a\u30a2\u30c9\u30ec\u30b9\u306e\u7bc4\u56f2 (16MB, 4GB, \u305d\u308c\u4ee5\u4e0a\u3001\u306a\u3069)\n<li>DMA\u7528\u306e\u30e1\u30e2\u30ea\u306e\u5408\u8a08\u306e\u6700\u5927\u30b5\u30a4\u30ba\n<li>\u4e0a\u8a18\u30e1\u30e2\u30ea\u3092\u6700\u5927\u3044\u304f\u3064\u306e\u30bb\u30b0\u30e1\u30f3\u30c8\u306b\u5206\u5272\u3057\u3066\u3088\u3044\u304b\u3001\u30bb\u30b0\u30e1\u30f3\u30c8\u30b5\u30a4\u30ba\u306e\u4e0a\u9650\u306f\u3044\u304f\u3089\u304b\n<\/ul>\n<p>DMA tag \u3092\u4f5c\u308b\u3060\u3051\u3067\u306f\u30e1\u30e2\u30ea\u306f\u78ba\u4fdd\u3055\u308c\u307e\u305b\u3093\u3002<\/p>\n<li>bus_dmamap_create()<br \/>\n\u30bf\u30b0\u306e\u60c5\u5831\u306b\u57fa\u3065\u3044\u3066 map \u3092\u751f\u6210\u3057\u307e\u3059\u3002\u3072\u3068\u3064\u306e\u30bf\u30b0\u306b\u5bfe\u5fdc\u3059\u308b\u8907\u6570\u306e map \u3092\u751f\u6210\u3067\u304d\u307e\u3059\u3002map \u3060\u3051\u3067\u3001\u5b9f\u969b\u306e\u30e1\u30e2\u30ea\u306f\u78ba\u4fdd\u3055\u308c\u306a\u3044\u3063\u307d\u3044\u3002<\/p>\n<li>bus_dmamem_alloc()<br \/>\n\u3053\u3053\u3067malloc() \u304b contigmalloc() (\u78ba\u4fdd\u3059\u308b\u9818\u57df\u306e\u30b5\u30a4\u30ba\u6b21\u7b2c\u3067\u3059\u306d) \u304c\u547c\u3070\u308c\u307e\u3059\u3002\u78ba\u4fdd\u3055\u308c\u308b\u30b5\u30a4\u30ba\u306f tag \u3092\u4f5c\u308b\u3068\u304d\u306b\u6307\u5b9a\u3057\u305f\u6700\u5927\u30b5\u30a4\u30ba\u3002\u7269\u7406\u30a2\u30c9\u30ec\u30b9\u306f\u5206\u6563\u3057\u3066\u3044\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u30ab\u30fc\u30cd\u30eb\u4eee\u60f3\u30a2\u30c9\u30ec\u30b9\u7a7a\u9593\u3067\u306f\u9023\u7d9a\u3057\u305f\u9818\u57df\u306b\u306a\u308a\u307e\u3059 (\u305f\u3076\u3093)\u3002<\/p>\n<li>bus_dmamap_load()<br \/>\n\u6700\u5f8c\u306b\u3053\u308c\u3067\u30c7\u30d0\u30a4\u30b9\u5074\u304b\u3089\u898b\u3048\u308b\u30a2\u30c9\u30ec\u30b9\u306e\u30ea\u30b9\u30c8\u3092\u53d7\u3051\u53d6\u308a\u307e\u3059\u3002bus_dmamap_load() \u3067\u306f\u3059\u3050\u306b\u30ea\u30b9\u30c8\u304c\u3082\u3089\u3048\u306a\u304f\u3066\u3001callback \u95a2\u6570\u3092\u6307\u5b9a\u3057\u3066\u304a\u3044\u3066\u3001\u304a\u308f\u308b\u3068\u7d50\u679c\u304c\u5e30\u3063\u3066\u304f\u308b\u611f\u3058\u3067\u3059\u3002\n<\/ol>\n<p>\u7247\u4ed8\u3051\u308b\u3068\u304d\u306f\u9006\u9806\u3067\u3059\u3002<\/p>\n<ol>\n<li>bus_dmamap_unload()\n<li>bus_dmamem_free()\n<li>bus_dmamp_destroy()\n<li>bus_dma_tag_destroy()\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>FreeBSD \u3067\u30c7\u30d0\u30a4\u30b9\u30c9\u30e9\u30a4\u30d0\u66f8\u3044\u3066 DMA \u3092\u52d5\u304b\u3059\u305f\u3081\u306e\u3044\u308d\u3044\u308d\u3002\u3068\u308a\u3042\u3048\u305a\u53c2\u8003\u306b\u306a\u308a\u305d\u3046\u306a\u306e\u306f\u3001 FreeBSD Architecture Handbook: Bus Memory Mapping bus_dm &hellip; <a href=\"https:\/\/yasu2.prosou.nu\/blog\/index.php\/2013\/05\/17\/2667\/\" class=\"more-link\"><span class=\"screen-reader-text\">&#8220;FreeBSD device driver \u3067 DMA&#8221; \u306e<\/span>\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":4,"activitypub_interaction_policy_quote":"anyone","activitypub_status":"","footnotes":""},"categories":[6],"tags":[],"class_list":["post-2667","post","type-post","status-publish","format-standard","hentry","category-unix-"],"_links":{"self":[{"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/2667","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=2667"}],"version-history":[{"count":0,"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/posts\/2667\/revisions"}],"wp:attachment":[{"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=2667"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=2667"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yasu2.prosou.nu\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=2667"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}